Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) is required for the estradiol-dependent increase of phosphatase and tensin homolog (PTEN) protein expression.
Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) is required for the estradiol-dependent increase of phosphatase and tensin homolog (PTEN) protein expression.
复制标题
DOI：
10.1210/en.2011-1207
复制
发表时间：
2011-10
期刊：
影响因子：
4.8
通讯作者：
Long-yan Yang;Ying Wang;Peng Chen;Jia Hu;Ying Xiong;Duiping Feng;Hua Liu;Hong Zhang;
中科院分区：
文献类型：
--
作者：
Long-yan Yang;Ying Wang;Peng Chen;Jia Hu;Ying Xiong;Duiping Feng;Hua Liu;Hong Zhang;
雌激素可在转录后水平诱导10号染色体上缺失的磷酸酶和紧张素同源物（PTEN）的表达。然而，这一过程的分子机制尚不清楚。在本研究中，我们发现PTEN的C端（CT）对于17-β-雌二醇（E2）增加PTEN的表达是不可或缺的。因此，我们使用谷胱甘肽- s -转移酶下拉方法结合基于质谱的蛋白质组学分析筛选pten - ct相关蛋白。我们的实验确定Na(+)/H（+）交换调节因子1 （NHERF1）是PTEN-CT的主要结合伙伴。NHERF1的第一个突触后密度蛋白-95/Discslarge/zonula occludens-1同源结构域和PTEN的最后四个氨基酸被发现是这种相互作用的关键决定因素。通过NHERF1过表达实验和小干扰rna介导的敲低实验证明，NHERF1通过与PTEN结合，可以通过保留PTEN的周转来增强PTEN蛋白的表达。此外，NHERF1通过与PTEN结合的竞争抑制PTEN蛋白的泛素化，PTEN与神经前体细胞表达，发育下调4，泛素E3连接酶。E2仅在雌激素受体（ER）阳性细胞中强烈诱导NHERF1和PTEN的表达，而在雌激素受体（ER）阴性细胞中则没有。er特异性抑制剂ICI182780降低了NHERF1和PTEN的表达，并且ICI182780预处理也延缓了e2升高的PTEN在ER-MDA-MB-231细胞中的表达。在ER-MDA-MB-231和MCF-7细胞中，当NHERF1被敲除时，E2未能增加PTEN的表达。综上所述，这些结果首次揭示了e2增加PTEN表达的可能机制。在这个过程中，E2首先通过激活ER诱导NHERF1表达。在与表达的神经前体细胞竞争后，发育下调4，NHERF1然后通过泛素化依赖途径与PTEN相互作用以抑制PTEN的降解。这反过来又导致PTEN在蛋白水平上的表达增加。
Expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) can be induced by estrogens at the posttranscriptional level. However, the molecular mechanism of the process is unclear. In this study, we found that the C terminus (CT) of PTEN is indispensable for 17-β-estradiol (E2)-increased PTEN expression. Therefore, we screened for PTEN-CT-associated proteins using a glutathione-S-transferase pull-down approach in combination with mass spectrometry-based proteomic analyses. Our experiments led to the identification of Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) as a major PTEN-CT binding partner. The first postsynaptic density protein-95/Discslarge/zonula occludens-1 homology domain of NHERF1 and the last four amino acids of PTEN were found to be key determinants of this interaction. By associating with PTEN, NHERF1 could enhance PTEN protein expression by retention of PTEN turnover, as demonstrated by NHERF1 overexpression and small interfering RNA-mediated knockdown experiments, respectively. Furthermore, NHERF1 inhibited ubiquitination of the PTEN protein upon competition with binding of PTEN to neural precursor cell expressed, developmentally down-regulated 4, an ubiquitin E3 ligase. E2 strongly induced the expression of NHERF1 and PTEN only in estrogen receptor (ER)-positive cells but not in ER-negative cells. ICI182780, an ER-specific inhibitor, decreased the expression of both NHERF1 and PTEN, and ICI182780 pretreatment also retarded E2-increased PTEN expression in ER-MDA-MB-231 cells. In both ER-MDA-MB-231 and MCF-7 cells, E2 failed to increase PTEN expression when NHERF1 was knocked down. Taken together, these are the first results that present a possible mechanism for E2-increased PTEN expression. In this process, E2 first induces NHERF1 expression by activating the ER. Upon competition with neural precursor cell expressed, developmentally down-regulated 4, NHERF1 then interacts with PTEN to inhibit PTEN degradation, through an ubiquitination-dependent pathway. This in turn leads to the increase of PTEN expression at the protein level.